Railway-traffic-controlling apparatus



March 16 1926. 1,576,944

. H. G. BLOSSER RAILWAY TRAFFIC CONTROLLING APPARATUS Original Fi1ed Jan. 8, 1924 INVENTOR Z Patented Mar. 16, 1925.

UNITED STATES 1,576,944 PATENT- OFFICE.

HERMAN G. BLOSSER, 035 SWISSVALE, PENNSYLVANIA, ASSIGNOR TO THE UNION SWITCH & SIGNAL COMPANY, OF SVVISSVALE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

RAILWAY-TRAFFIC-CONIROLLING APPARATUS.

Application filed January 8. 2924, Serial To a? Z 20720122. it may 0011061 12..

Be it known that l, HERMAN G. BLossn -i,

a citizen of the United States. residing at I Swissvale, in the county of Alleghenyand 5 State of Pennsylvaniiu have invented certain new and useful Iu'iprovements in Railway-Tratlic-Controlling .Apparatus, of which the following is a specification.

My invention relates to railway trafiic controlling apparatus and particularly to apparatus of the type comprising loop circuits or local circuits for the control of. train carried governing means.

I will describe one form of trackway apparatus embodying my invention, and will then point out the novel features thereof in claims.

The accompanying drawing is a diagrammatic view showingone form of traclrway apparatus embodying my invention.

Referring to this drawing, the reference characters 1 and 1 designate the track rails of an electric railway. Propulsion current is supplied to these rails through an impedance 5 and to a trolley or third rail 6,

from a suitable source of energy such as a generator E. As here shown, the propulsion current is an alternating current. The track rails 1 and 1 are divided, by means of insulated joints 2, into a plurality of successive sections A-B, BC, CD, etc. Propulsion current is conducted past. each pair of insulated joints by an impedance bond H. Referring particularly to the impedance bond H at point B, this bond comprises two impedances 3 and 3, connected across the rails adjacent the right-hand end of section fir-B and across the rails adjacent the lefthand end of section B--C, respectively.

The mid points of these impedances 3 are connected together by a conductor 4. in the usual manner.

Each track circuit is provided with a loop circuit which is supplied with alternating loop current from a loop transformer designated by the reference character T with an exponent corresponding to the location. Primary 8 of each loop transformer T is constantly supplied with alternating current 50 from an alternator Gr, over line wires '7 and R-eferring particulaly to section A B,

the loop circuit for this section passes from secondary 10 of transformer T through Wire 13, winding 11 of an inductive 1m- No. 684,951. Renewed January 2%, 1926.

pedance J wires and l, and impedance 8 at point B to the rails of section A.B. thence through the rails of section A 1; to impedance 3 at point A, wires 4, H and 16, impedance l7 and wire 18 hackto secondary 10 of transformer T Theloop circuit for section B@ may he traced from secondary 9. of transformer T, through wire 19, winding 12 of inductive impedance J wires 20 and l, impedance 3" at point B, the rails of section BC, impedance 3 at point C, wires l, 15 and 21, impedance 22 and wire hack to secondary 9 of'transformer One purpose of inipedances l7 and 22 is to adjust the currents through the respective circuits to the proper value.

The loop currents may he utilized to control traffic in any desired manner.

Under certain conditions a voltage drop is established between the two ends of a section due to the flow of propulsion current in the rails of the section. It is desirable to prevent the flow of propulsion current in the loop circuits to prevent burning out i1npedances 17 and 22 and the windings of the loop transformers. Itis also desirable to prevent the propulsion current from feeding hack into line wires 7 and'l'. It should he noted that in apparatus embodying my in- Wntion the propulsion current voltage drop is not effective to .send a heavy current through the loop circuit due to the manner of connecting the inductive ilnpedances .l. Referring again to the apparatus located adjacent point B, it will he seen that loop current: from secondary 10 of transformer 'l flows through winding 11 of impedance J in one direction, and loop current from winding 9 of transformer 'l flowsthrough winding 12 of impedance J in the other direction. That is, the loop currents in the two portions of in'ipedance J are of opposite relative polarity, so that the opposition offered to the flow of these currents by impedance J is very small. On the other hand. propulsion current tends to now through both portions of this impedance in the same direction at any instant. For example when propulsion current tends to flow from point C from right to left through winding 12 of impedance J to point B, propulsion current also tends to flow from point B from right to left through winding 11 of impedance U to Ep'o-int A. It will be clear that these two currents oppose each other and as a result the opposition offered to the flow of such currents "by impedance 1;! is

comparatively large and the propulsion "CUT- rent flowing in the loop circuits is limited to a small value.

Although I have lieiein 's'hown a m atscribed only one form and arrangement of trackway apparatus eiiibodyi'n g my inye'i'r tion, it is understood that various changes and modifications may be 'made therein within the scope of the app" ded claims without departing 'Efi'omt'he sp It and scope of my invention.

Having thus described my invention, what. I claim is i 1. Railva tra'flic controlling appa"atus comprising a stretch of track divided into .a forward and a rear track section, an impedance having two portions, a loop circuit for said forward section including one Dortion of said impedance, and a loop circuit for the rear section including the other portion of the impedance.

2. In combination, two adjoining sections of railway track, an impedance having its mid point connected with the adjacent ends of said sections, means for applying an alternating elect-romotive force from one terminal of said impedance 'to the free end of one section, and means for supplying an alternating electromo'tive force opposite to the instantaneous relative polarity of said first electromoti e :torce from the remaining end of said impedance to the free end ofthefsecond said track vsection.

In combination, a forward and a rear track section, an impedance comprising two portions, means for supplying loop current of one relative polarity to said forward section and to one portion of "saidimpedance, and means for s'upplying loopcurrent of the other relative polarity to said rear section arndtothe remaining portion of "said imped- 'ance.

'4. In combination, a forward and a rear track section, an impedance bond for conducting propulsion current from one said Section to the other, an impedance having 'itsmid point connected with said impedance bond, two sources of alternating current,

and means io'r connecting one said source from the free end of one section to one terminal of said impedance and for connecting theother said source from the free end of the rei'naini'ng section to the remaining terminal of said impedance.

Railway traiiic controlling apparatus comprising a forward and a. rear stretch of railway "track, an impedance having its mid point connected with the 'rear end oi". said "forward section and with the forward end or said rear section, a loop transformer fhai'i'ng two secondaries, means for connectingt'he le it-hand end'ofone said secondarv with one terminal of said impedance and for connecting the right-hand end of said secondary with "the forward end of said "forward section, and means for connecting the left-hand end of. the remaining secondary with the remaining terminal of said impedand for connecting the right-hand end of said remaining secondary with the rear end of said rear section.

6. In combination, a plurality of successite sections of railway track, an impedance "for each two track sections located adjacentthe jimoture-of such sections, and means for supplying "alternating current to each sec 'tion and a portion-of the associated "impedance, the current so-supplied to'the two portions of each impedance being of opposite instantaneous polarities.

"Intestimony whereof I my signature.

HERMAN G. BLQS'SEH. 

